Jason,
When you install Windows 2000 Server onto a system you simply have a server
running WIN2000 Server at this point. It may or may not be joined to a
domain ( so, it is either a member of a domain or it is in a workgroup ).
The way that you create a Domain Controller is to take that system running
WIN2000 Server and run 'dcpromo' on it. This process will make it a Domain
Controller ( with everything that this entails - short story is that it now
has ntds.dit in the default location of c:\winnt\ntds ). You will have
several choices ( add a Domain Controller to an existing domain or create a
new domain et al ).
Now, if this particular system running WIN2000 Server is already a Domain
Controller running 'dcpromo' will - and I am creating a new word in the
English language - unDomainControllerize it! Translation - that Domain
Controller is no longer a Domain Controller ( meaning, ntds.dit is
removed ). You could just as easily then run 'dcpromo' on that very same
server to make it a Domain Controller again. Hopefully you get the point
here.
If you have a Domain Controller then you have a Domain. If you do not have
a Domain Controller then you have no domain. In WIN2000 Active Directory
indicates a Domain.
HTH,
Cary